No one can speak/write perfect English these days. Maile bhaneko haina, experts harule bhaneko. Office for Standards in Education (England) had set up a commission soliciting recommendations from experts about improvement of English(language) education in the UK few months ago. The commission presented its report and identified grammatical errors as one of the big problems. But the irony was that there were dozens of grammatical errors in the report itself. English is a global language and it has learnt to adapt localization. Hence it is impossible to expect uniformity. Avoiding silly mistakes holds the key. As far as American and British English are concerned, I find the sweetness in the original version. British English is definitely the best. I haven't been able to adapt, is a different matter :)